Improved Differential Privacy Noise Mechanism in Quantum Machine Learning

Quantum computing, as an emerging research field, is attracting people's attention. It has been proven to be superior in many ways to classical computing. Differential privacy provides an easy way to achieve demonstrable privacy, and the most common method is to add noise to datasets. At this stage of quantum computers, noise is a factor that cannot be ignored. Indeed, the existence of noise will negatively affect the performance of quantum computers, but we can apply it to privacy protection. In this work, we will consider two situations: inherent noise and artificially added noise. The noise is added to the variational quantum algorithm to implement quantum machine learning with differential privacy. The importance of each type will be examined and less artificial noise is needed for a common privacy budget over classical machine learning. Composition theory will be invoked to prove the advantage of the entire quantum machine learning process.